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Miniaturized piezoelectric actuators for high-speed flow control applications.

Abstract : This work describes the development of miniaturized piezoelectric actuators for high-speed flow control on airfoils. The goal is to delay the laminar-turbulent transition by active wave cancellation of so-called Tollmien-Schlichting waves introducing appropriate counterwaves. The first design concept is based on a mechanically amplified actuator where an external elas-tic lever-type amplification unit is located above a piezoelectric disc. This actuator provides direct control ability, a linear transfer function, and fast response time facilitating its integra-tion in controller systems. The second design concept is based on a tapered membrane driven in one of its axisymmetric eigenmodes, excited by a piezoelectric ring placed at the outer edge. The tapered membrane focuses the induced waves to the centre, where maximum amplitudes can be observed. Ampli-tude modulation allows the actuator to attain a wide frequency range as required for active cancellation of Tollmien-Schlichting waves, where the carrier frequency is provided by the eigenfrequencies. Its robustness, simple fabrication, and closed surface qualify this actuator for aircraft implementation. The effect of both actuators on the airflow around a wing profile at open-loop control has been measured with hot-film anemometers during a wind tunnel experiment. For device di-mensions adapted to the flow conditions both actuators exhibit the desired effect on the air-flow required for active transition control. It has been shown that amplitude modulation is an option for this type of flow control if the carrier frequency is selected adequately (>40 kHz) in order to not disturb the airflow.
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https://pastel.archives-ouvertes.fr/pastel-00573967
Contributor : Christian Bolzmacher <>
Submitted on : Sunday, March 6, 2011 - 3:00:07 PM
Last modification on : Wednesday, March 9, 2011 - 2:34:01 PM
Long-term archiving on: : Tuesday, June 7, 2011 - 2:27:03 AM

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  • HAL Id : pastel-00573967, version 1

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Citation

Christian Bolzmacher. Miniaturized piezoelectric actuators for high-speed flow control applications.. Materials and structures in mechanics [physics.class-ph]. Ecole Polytechnique X, 2010. English. ⟨pastel-00573967⟩

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